This symbol is a type alias.
Source:
NestedSpec = Union[
tensorflow.python.framework.type_spec.TypeSpec,
tensorflow.python.framework.tensor.TensorSpec,
tensorflow.python.ops.ragged.ragged_tensor.RaggedTensorSpec,
tensorflow.python.framework.sparse_tensor.SparseTensorSpec,
tf_agents.types.DistributionSpecV2
,
Iterable[ForwardRef('NestedTensorSpec')],
Mapping[str, ForwardRef('NestedTensorSpec')],
tf_agents.types.ArraySpec
,
Iterable[ForwardRef('NestedArraySpec')],
Mapping[str, ForwardRef('NestedArraySpec')]
]